1. Field of the Invention
The present invention relates to a magnetic head for use in a VTR or the like and a method of manufacturing the same.
2. Description of the Related Art
Metal-in-gap (MIG) heads which employ a F--Si--Al (Sendust) alloy or an amorphous alloy such as Co--Nb--Zr in the vicinity of a magnetic gap and which employ a Mn--Zn ferrite as a back core have been known. Such MIG type heads, in which a metal magnetic alloy film having a high saturation magnetic flux density (4'.pi.Ms) is disposed in the vicinity of the magnetic gap, have improved recording characteristics over magnetic heads which are made of a ferrite alone. FIG. 1 shows an example of such an MIG type head. In FIG. 1, a reference numeral 1 denotes a ferrite back core, 2 a metal magnetic alloy film, 3 a magnetic gap portion made of SiO.sub.2 or the like, and 4 a bonding glass.
However, magnetic heads which employ F--Si--Al system alloys as the metal magnetic film suffer from a problem that Al is segregated in an interface 5 between the metal magnetic alloy film 2 and the ferrite core 1. Magnetic heads which employ amorphous Co--Nb--Zr system alloys as the head cores have a problem in that Nb or Zr deprives the ferrite of oxygen to generate an affected layer, which may lead to generation of a false gap and degradation of the characteristics of the magnetic head. Furthermore, it is very difficult to control the magnetic anisotropy of the F--Si--Al alloy film, and the characteristics of the F--Si--Al alloy film incorporated in the magnetic head easily varies. Control of the magnetic anisotropy of the Co--Nb--Zr amorphous alloy film is possible by means of heat treatment of the alloy film in that anisotropy of the Co--Nb--Zr alloy film disappears unless the amorphous alloy remains in the presence of a magnetic field throughout the heat treatment. A Co--Nb--Zr amorphous alloy film having a high saturation magnetization has a low crystallization temperature, and this makes the glass bonding process thereof in the vicinity of 500.degree. C. very difficult. Further, the use of a normal ferrite in a magnetic head generates sliding noises, so the MIG head has a deteriorated C/N or S/N ratio as compared to a metal head.